An apparatus described in a patent document 1 described later is a conventional valve timing control apparatus.
This apparatus includes a pulley which has a cylindrical bottomed shape, which includes a cylindrical wall and a bottom wall, and to which a rotational force is transmitted from a crank shaft through a timing belt; a housing which has an annular shape, which is received within the pulley, and which includes front and rear opening ends closed by a pair of disc plates; and a vane rotor which is received within the housing to be rotated relative to the housing, and which is fixed to an end portion of a cam shaft. Advance angle hydraulic chambers and retard angle hydraulic chambers are separated between a plurality of shoes protruding from the inner circumference surface of the housing from a diameter direction in inward directions, and a plurality of vanes of the vane rotor.
The housing including disc-shaped plates is fixed on the bottom wall of the pulley by bolts. An annular clearance is formed between the outer circumference surface of the housing, and the inner circumference surface of the cylindrical wall of the pulley. The annular clearance has a relatively large width for decreasing an entire weight of the apparatus.